Astronomy quiz question: origins of Earth's elements

Astronomy 210 Quiz 7, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

[Version 1]

Fusion reactions in the core of another main-sequence star produced the:
(A) hydrogen in Jupiter's atmosphere.
(B) carbon in your body.
(C) gold and silver in Earth's crust.
(D) (None of the above choices.)

Correct answer: (B)

All "metals" (elements heavier than hydrogen) on Earth must have been produced by a previous generation star. Reactions in the cores of stars fuse hydrogen into heavier elements, notably carbon, and others up through iron. Type Ia supernovae and type II supernovae explosions will fuse elements heavier than iron, such as gold and silver.

Section 30674
(A) : 5 students
(B) : 9 students
(C) : 22 students
(D) : 5 students

"Success level": 27% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.09

[Version 2]

Fusion reactions in the core of the sun produced the:
(A) hydrogen in Jupiter's atmosphere.
(B) carbon in your body.
(C) gold and silver in Earth's crust.
(D) (None of the above choices.)

Correct answer: (D)

Since Earth was formed out of the same nebular disk as the sun, the elements in everything on Earth were produced from a previous generation of stars, and not from the fusion reactions in the core of the sun.

Section 30676
(A) : 12 students
(B) : 14 students
(C) : 23 students
(D) : 19 students

"Success level": 33% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.40